from synapse.api.ratelimiting import LimitExceededError, Ratelimiter from synapse.appservice import ApplicationService from synapse.config.ratelimiting import RatelimitSettings from synapse.types import create_requester from tests import unittest class TestRatelimiter(unittest.HomeserverTestCase): def test_allowed_via_can_do_action(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings(key="", per_second=0.1, burst_count=1), ) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", _time_now_s=0) ) self.assertTrue(allowed) self.assertEqual(10.0, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", _time_now_s=5) ) self.assertFalse(allowed) self.assertEqual(10.0, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", _time_now_s=10) ) self.assertTrue(allowed) self.assertEqual(20.0, time_allowed) def test_allowed_appservice_ratelimited_via_can_requester_do_action(self) -> None: appservice = ApplicationService( token="fake_token", id="foo", rate_limited=True, sender="@as:example.com", ) as_requester = create_requester("@user:example.com", app_service=appservice) limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( key="", per_second=0.1, burst_count=1, ), ) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=0) ) self.assertTrue(allowed) self.assertEqual(10.0, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=5) ) self.assertFalse(allowed) self.assertEqual(10.0, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=10) ) self.assertTrue(allowed) self.assertEqual(20.0, time_allowed) def test_allowed_appservice_via_can_requester_do_action(self) -> None: appservice = ApplicationService( token="fake_token", id="foo", rate_limited=False, sender="@as:example.com", ) as_requester = create_requester("@user:example.com", app_service=appservice) limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( key="", per_second=0.1, burst_count=1, ), ) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=0) ) self.assertTrue(allowed) self.assertEqual(-1, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=5) ) self.assertTrue(allowed) self.assertEqual(-1, time_allowed) allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(as_requester, _time_now_s=10) ) self.assertTrue(allowed) self.assertEqual(-1, time_allowed) def test_allowed_via_ratelimit(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings(key="", per_second=0.1, burst_count=1), ) # Shouldn't raise self.get_success_or_raise(limiter.ratelimit(None, key="test_id", _time_now_s=0)) # Should raise with self.assertRaises(LimitExceededError) as context: self.get_success_or_raise( limiter.ratelimit(None, key="test_id", _time_now_s=5), by=0.5 ) self.assertEqual(context.exception.retry_after_ms, 5000) # Shouldn't raise self.get_success_or_raise( limiter.ratelimit(None, key="test_id", _time_now_s=10) ) def test_allowed_via_can_do_action_and_overriding_parameters(self) -> None: """Test that we can override options of can_do_action that would otherwise fail an action """ # Create a Ratelimiter with a very low allowed rate_hz and burst_count limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings(key="", per_second=0.1, burst_count=1), ) # First attempt should be allowed allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action( None, ("test_id",), _time_now_s=0, ) ) self.assertTrue(allowed) self.assertEqual(10.0, time_allowed) # Second attempt, 1s later, will fail allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action( None, ("test_id",), _time_now_s=1, ) ) self.assertFalse(allowed) self.assertEqual(10.0, time_allowed) # But, if we allow 10 actions/sec for this request, we should be allowed # to continue. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, ("test_id",), _time_now_s=1, rate_hz=10.0) ) self.assertTrue(allowed) self.assertEqual(1.1, time_allowed) # Similarly if we allow a burst of 10 actions allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, ("test_id",), _time_now_s=1, burst_count=10) ) self.assertTrue(allowed) self.assertEqual(1.0, time_allowed) def test_allowed_via_ratelimit_and_overriding_parameters(self) -> None: """Test that we can override options of the ratelimit method that would otherwise fail an action """ # Create a Ratelimiter with a very low allowed rate_hz and burst_count limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings(key="", per_second=0.1, burst_count=1), ) # First attempt should be allowed self.get_success_or_raise( limiter.ratelimit(None, key=("test_id",), _time_now_s=0) ) # Second attempt, 1s later, will fail with self.assertRaises(LimitExceededError) as context: self.get_success_or_raise( limiter.ratelimit(None, key=("test_id",), _time_now_s=1), by=0.5 ) self.assertEqual(context.exception.retry_after_ms, 9000) # But, if we allow 10 actions/sec for this request, we should be allowed # to continue. self.get_success_or_raise( limiter.ratelimit(None, key=("test_id",), _time_now_s=1, rate_hz=10.0) ) # Similarly if we allow a burst of 10 actions self.get_success_or_raise( limiter.ratelimit(None, key=("test_id",), _time_now_s=1, burst_count=10) ) def test_pruning(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings(key="", per_second=0.1, burst_count=1), ) self.get_success_or_raise( limiter.can_do_action(None, key="test_id_1", _time_now_s=0) ) self.assertIn("test_id_1", limiter.actions) self.get_success_or_raise( limiter.can_do_action(None, key="test_id_2", _time_now_s=10) ) self.assertNotIn("test_id_1", limiter.actions) def test_db_user_override(self) -> None: """Test that users that have ratelimiting disabled in the DB aren't ratelimited. """ store = self.hs.get_datastores().main user_id = "@user:test" requester = create_requester(user_id) self.get_success( store.db_pool.simple_insert( table="ratelimit_override", values={ "user_id": user_id, "messages_per_second": None, "burst_count": None, }, desc="test_db_user_override", ) ) limiter = Ratelimiter( store=store, clock=self.clock, cfg=RatelimitSettings("", per_second=0.1, burst_count=1), ) # Shouldn't raise for _ in range(20): self.get_success_or_raise(limiter.ratelimit(requester, _time_now_s=0)) def test_multiple_actions(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( key="", per_second=0.1, burst_count=3, ), ) # Test that 4 actions aren't allowed with a maximum burst of 3. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", n_actions=4, _time_now_s=0) ) self.assertFalse(allowed) # Test that 3 actions are allowed with a maximum burst of 3. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", n_actions=3, _time_now_s=0) ) self.assertTrue(allowed) self.assertEqual(10.0, time_allowed) # Test that, after doing these 3 actions, we can't do any more actions without # waiting. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", n_actions=1, _time_now_s=0) ) self.assertFalse(allowed) self.assertEqual(10.0, time_allowed) # Test that after waiting we would be able to do only 1 action. # Note that we don't actually do it (update=False) here. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action( None, key="test_id", update=False, n_actions=1, _time_now_s=10, ) ) self.assertTrue(allowed) # We would be able to do the 5th action at t=20. self.assertEqual(20.0, time_allowed) # Attempt (but fail) to perform TWO actions at t=10. # Those would be the 4th and 5th actions. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", n_actions=2, _time_now_s=10) ) self.assertFalse(allowed) # The returned time allowed for the next action is now even though we weren't # allowed to perform the action because whilst we don't allow 2 actions, # we could still do 1. self.assertEqual(10.0, time_allowed) # Test that after waiting until t=20, we can do perform 2 actions. # These are the 4th and 5th actions. allowed, time_allowed = self.get_success_or_raise( limiter.can_do_action(None, key="test_id", n_actions=2, _time_now_s=20) ) self.assertTrue(allowed) # We would be able to do the 6th action at t=30. self.assertEqual(30.0, time_allowed) def test_rate_limit_burst_only_given_once(self) -> None: """ Regression test against a bug that meant that you could build up extra tokens by timing requests. """ limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings("", per_second=0.1, burst_count=3), ) def consume_at(time: float) -> bool: success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=time) ) return success # Use all our 3 burst tokens self.assertTrue(consume_at(0.0)) self.assertTrue(consume_at(0.1)) self.assertTrue(consume_at(0.2)) # Wait to recover 1 token (10 seconds at 0.1 Hz). self.assertTrue(consume_at(10.1)) # Check that we get rate limited after using that token. self.assertFalse(consume_at(11.1)) def test_record_action_which_doesnt_fill_bucket(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( "", per_second=0.1, burst_count=3, ), ) # Observe two actions, leaving room in the bucket for one more. limiter.record_action(requester=None, key="a", n_actions=2, _time_now_s=0.0) # We should be able to take a new action now. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=0.0) ) self.assertTrue(success) # ... but not two. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=0.0) ) self.assertFalse(success) def test_record_action_which_fills_bucket(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( "", per_second=0.1, burst_count=3, ), ) # Observe three actions, filling up the bucket. limiter.record_action(requester=None, key="a", n_actions=3, _time_now_s=0.0) # We should be unable to take a new action now. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=0.0) ) self.assertFalse(success) # If we wait 10 seconds to leak a token, we should be able to take one action... success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=10.0) ) self.assertTrue(success) # ... but not two. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=10.0) ) self.assertFalse(success) def test_record_action_which_overfills_bucket(self) -> None: limiter = Ratelimiter( store=self.hs.get_datastores().main, clock=self.clock, cfg=RatelimitSettings( "", per_second=0.1, burst_count=3, ), ) # Observe four actions, exceeding the bucket. limiter.record_action(requester=None, key="a", n_actions=4, _time_now_s=0.0) # We should be prevented from taking a new action now. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=0.0) ) self.assertFalse(success) # If we wait 10 seconds to leak a token, we should be unable to take an action # because the bucket is still full. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=10.0) ) self.assertFalse(success) # But after another 10 seconds we leak a second token, giving us room for # action. success, _ = self.get_success_or_raise( limiter.can_do_action(requester=None, key="a", _time_now_s=20.0) ) self.assertTrue(success)